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As a promising technology for replacing the rule-based decision-making in region heating systems (RHS), deep reinforcement learning (DRL) is a practical solution to identify the optimal control for heating equipment. However, as residential customers perform more casual energy-consumption behaviors, the intermittency and volatility of heat demands make managing heat supply and storage much harder for DRL agents. This study proposes a novel predictive management method for campus heating systems (CHS) with air-source heat pumps (AHP) and thermostatic water tanks. The novelty of the proposed method lies in the combination of the heat demands forecasting model and DRL-based adaptively controlling for heat supply equipment, which is firstly proposed to improve the heating supply reliability and reduce the storage dependence for CHS. Specifically, an enhanced rule, namely minimum length hamming encoding, and an input array constructing method is introduced to deal with discrete feature data and then improve the accuracy of deterministic heat demands forecasting based on long-short term memory (LSTM), and the Kernel density estimation (KDE) are employed to obtain the prediction intervals (PIs) from H-step ahead heat demands forecasting series. Followed by these, the twin delayed deep deterministic policy gradient, a model-free DRL control algorithm, is adopted for adaptively adjusting the output flow rate of AHP and then the storage of the hot water tank. To demonstrate the validity of the proposed method, a case study is presented where a campus heat demands forecasting achieves a maximum accuracy gain of 4.52%, and an optimal AHP operating controlling determined from PIs achieves a better cost reduction and supply reliability, which is superior over the conventional method using real-time heat demands or deterministic forecasting results as input. • An adaptive management model for campus heating systems using the DRL algorithm is established. • Model predictive control theory is employed to cope with the intermittent nature of campus heat demands. • A more efficient encoding rule is proposed to improve the accuracy of LSTM-based deterministic demands forecasting. • Cosine function-based KDE is introduced to obtain the PIs of campus heat demands. • The proposed method can achieve a remarkable economic benefit and reduce the dependency on storage capacity for CHS. [ABSTRACT FROM AUTHOR]

A novel absorbing material with a flexible sandwich structure (S121) was designed and assembled using light-weight foams of Polydimethylsiloxane (PDMS) to achieve a full X-band absorption. The PDMS foams based on the composites of hollow polyaniline and MWCNTs (HPC) were prepared by means of impregnation technology selecting sugar cubes as a template. For the construction of sandwich S121, the upper and lower layers were HPC-PDMS foams (d foam = 1.0 mm) and the middle layer was HPC-PDMS film (d film = 0.5 mm). The SEM results revealed plentiful pores existed in S121, which would endow S121 with the traits of light-weight and lower density. The absorption performance of S121, single-layer HPC-PDMS foam (S1) and single-layer HPC-PDMS film (S2) had been characterized. Of importance, S121 achieved full absorption in X-band and its minimum reflection loss (RL min) reached −32.65 dB at 9.5 GHz. In contrast, the RL min of S1 and S2 were only −15.42 dB and −11.72 dB. The frequency regions with RL < −10 dB of S1 and S2 were surprisingly narrow, which were 1.5 GHz and 0.4 GHz, respectively. The results indicated that the design of S121 demonstrated a synergistic effect of foams and film, which was helpful to enhance absorption and realize an X-band full absorption. Of great significance, due to the excellent flexibility of S121, after bending and compressing many times, RL min value is nearly identical to that of original S121, and the effective bandwidth is also full coverage of X-band. The results showed that the proposed S121 design is feasible for applications in X-band. [Display omitted] • A flexible sandwich was designed and assembled based on PDMS foam and film. • The sandwich was constructed by filtering, absorbing and reverse interference layers. • The sandwich achieved a full X-band absorption and the RL min of −32.65 dB at 9.5 GHz. • The sandwich still kept admirable EM absorption after bending and compressing tests. [ABSTRACT FROM AUTHOR]

Abstract: Three novel low-bandgap (LGB) conjugated polythiophenes (PThBTD m Cz n ) incorporating separate and content-tunable benzothiadiazole and carbazole moieties have been designed and synthesized for application in bulk heterojunction polymer solar cells (PSCs). The absorption spectral, thermal, electrochemical and photovoltaic properties of the random copolymers were investigated. Broad absorption from a single polymer covering the visible region from 300 to 800nm was observed, which was ideal for highly efficient harvesting of the solar spectrum. DSC analysis showed that the polymers readily crystallized, indicating highly ordered intermolecular packing, which is beneficial for efficient charge-carrier transport. Electrochemical studies indicate desirable HOMO/LUMO levels that enable a high open-circuit voltage while blending them with fullerene derivatives as electron acceptors. Polymer solar cells using 1:1 or 1:2wt/wt polymer: PC61BM (methanofullerene [6,6-phenyl C61-butyric acid methyl ester] blends as the photoactive layers were fabricated and characterized. The preliminary investigation on the photovoltaic device of the PThBTD m Cz n polymers gave similar power conversion efficiency of 1.1–1.2% with V oc of 0.64–0.68V under simulated solar light AM 1.5 G (100mW/cm2). [Copyright &y& Elsevier]

Abstract: Two novel triphenylamine-substituted poly(p-phenylenevinylene) derivatives, P1 and P2, have been successfully synthesized through the Witting–Horner reaction. The structures and properties of the monomers and the resulting polymers were characterized by using 1H NMR, FT-IR, GPC, TGA, UV–vis absorption spectroscopy, cyclic voltammetry (CV) and electroluminescence (EL) spectroscopy. The obtained polymers exhibited good thermal stability and high photoluminescence quantum yield (0.42–0.90). The polymer light-emitting diodes (PLEDs) with the configuration of ITO/PEDOT/polymers/Ca/Al were fabricated. The single-layer device based on P1 and P2 emitted stable blue and yellow light with the turn-on voltage of 4 and 6V, respectively. The maximum luminance of 3003cd/m2 at 10V was obtained for device P2. [Copyright &y& Elsevier]